Colleagues of Japanese victims of last year's terrorist attacks in the United States solemnly observed the first anniversary on Wednesday, with many companies holding a moment of silence in remembrance of those who died when the World Trade Center buildings collapsed.

"They were innocent," a Mizuho Financial Group employee said, "If only I could turn back the clock to one year ago, I would want to prevent what has happened."

Twelve Japanese and seven local staff of Mizuho's New York office died in the attack.